T-square clamp.



UNITED STATES Patented July 7, 1903.

ALFRED SANG, OF PITTSBURG, PENNSYLVANIA.

T-SQUARE CLAMP.

SPECIFICATION forming part of Letters Patent No. 733,279, dated July '7,1903.

Application filed December 22, 1902. Serial No. 136,118. (No model.)

To ctZZ whom it may concern:

Be it known that I, ALFRED SANG, of Pittsburg, Allegheny county,Pennsylvania, have invented a new and useful T-Square Clamp, of whichthe following is a full, clear, and exact description, reference beinghad to the accompanying drawings, forming part of this specification, inwhich Figure 1 is a sectional side elevation showing the end portion ofa T-square provided with my improved clamp. Fig. 2 is a plan view.

My invention relates to the T-squares employed by draftsmen, and isdesigned to provide an improved clamp and guide for holding it inadjusted position to the table and guiding it in movements along thetable and which may be easily released and reclamped.

In the drawings, 2 represents the head of the T-square, 3 the blade, and4 an end portion of a table on which the square is used. The head of theT-square is provided with a hole through which extends a hollow plug 5,having at one side a downward extension 6 with a flat guiding-face 7 onits front side. This plug has a ring or flanged portion 8, fitting onthe top face of the head, and through it extends a thumb-screw 9, whosescrewthreaded portion 10 extends through an innerly-screw-threaded holein the sliding jaw 11. A spiral spring 12 is interposed between the jaw11 and the plug, which normally tends to force the jaw downwardly.

In operating the device the T-square is moved along with the edge of thetable to the desired point, and the thumb-screw is then turned to drawthe movable jaw upwardly against the under face of the table to clampthe device upon the table. The T-square may be released by turning thethumb-screw in the reverse direction, giving a quick and easyadjustment. In order to prevent tipping of the T-square when tightlyclamped, I preferably extend the flange 8, as shown at 8, this beingabove the jaw 11 and prevents a tendency to tilt.

When the device is partially clamped, it will prevent minute shiftingsof the T-square head and keepthe head squarely against the edge of theboard or table, while allowing the T-square to be moved up and down oralong this edge. It will also prevent the T-square from slipping down aninclined drawingboard.

The advantages of my invention result from the use of the clampextending transversely through the head and provided with the jaw, whichis forced against the under side of the table, since a quick and readyadjustment is afiorded, while the device may be cheaply made andapplied.

The clamp can be applied to a swivel-head T-square and changes may bemade in the form and arrangement of the clamp within the scope of myinvention.

I claim 1. A T-square having a clamping-stem extending through atransverse hole in its head, a stiff clamping-jaw supported on the stemand projecting sidewise beneath the T-square blade, said jaw beingarranged to be forced against the under side of the table by turning thestem, and a spring arranged to force back the clamping-jaw whenreleased; substantially as described.

2. A T-square having a transverse hole through its head, a hollow plugin the hole, a thumb-screw extending through the plug, a sliding jawmounted on the screw and projecting sidewise to a point below thethinner blade of the square and arranged to be forced against the table,and a spring between the plug and jaw; substantially as described.

3. A T-square having a transverse hole through its head, a hollow plugin the hole having a guiding extension, a jaw sliding along saidextension, and a thumb-screw extending through the plug and arranged toadjust the jaw; substantially as described.

In testimony whereof I have hereunto set my hand.

ALFRED SANG.

Witnesses:

F. O. I-IoDKINsoN, C. A. GLASER.

